Wind turbine component, wind turbine, and method for manufacturing of a wind turbine component

ABSTRACT

A wind turbine component adapted to be attached to a wind turbine, wherein the component is a cover element adapted to cover at least one part of a wind turbine or an aerodynamic element adapted to be attached to a rotor blade of a wind turbine, wherein the component includes a main body with a continuous and at least partly curved surface, wherein the main body is formed by a layer stack including a plurality of layers, wherein at least two of the layers are of a different material.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to PCT Application No.PCT/EP2021/074930, having a filing date of Sep. 10, 2021, which claimspriority to EP Application No. 20199578.4, having a filing date of Oct.1, 2020, the entire contents both of which are hereby incorporated byreference.

FIELD OF TECHNOLOGY

The following relates to a wind turbine component adapted to be attachedto a wind turbine, wherein the component is a cover element adapted tocover at least one part of a wind turbine or an aerodynamic elementadapted to be attached to a rotor blade of a wind turbine. Furthermore,the following relates to a wind turbine and a method for manufacturingof a wind turbine component.

BACKGROUND

Modern wind turbines tend to grow in size so that also their componentsand/or additional components that are attachable to the wind turbine inorder to enhance their performance become larger. For larger components,also their manufacturing process becomes cumbersome and/or moredifficult. In addition to the size of the components, also the loadsacting on the components during operation of the wind turbine increaseso that the manufacturing process has to be adapted taking into accountthe increasing loads.

It is known to manufacture components like cover elements and/oraerodynamic elements by extrusion or by vacuum injection. Thesemanufacturing processes have the disadvantage that they may be costlyfor producing larger components and that they may require a largercomponent thickness in order to fabricate sufficiently strongcomponents. However, an increased thickness matching the higher loadsacting on the component during operation of the wind turbine maynegatively affect the aerodynamic performance of the component, forinstance by steps in height, and/or its usability for attachment to awind turbine. In addition, the increased thickness leads to an increasedmass of the component, which is not desirable for attachments for a windturbine since it may affect for instance the attachment process of thecomponent and/or the performance of the wind turbine.

SUMMARY

An aspect relates to provide an improved wind turbine component and animproved method for manufacturing a wind turbine component.

According to embodiments of the invention, this aspect is solved by awind turbine component as initially described, wherein the componentcomprises a main body with a continuous and at least partly curvedsurface, wherein the main body is formed by a layer stack comprising aplurality of layers, wherein at least two of the layers consist of adifferent material.

Forming the main body of the wind turbine component from a layer stackcomprising a plurality of layers allows for adapting the properties ofthe component by choosing the material of the layers and/or thecomposition of the layer stack. This provides additional design optionsfor adapting the component to expected external loads during operationof the wind turbine, or the component, respectively. Different layers ofthe layer stack of the main body may fulfill different functions, likeproviding a mechanical stability of the component and/or anenvironmental protection and/or the like.

Furthermore, a main body comprising a continuous and at least partlycurved surface formed from a layer stack comprising a plurality oflayers may be fabricated advantageously using a stack of multiple layersand a vacuum forming process. By providing a stack of layers, inparticular planar or essentially planar layers and/or parallel oressentially parallel layers, prior to the vacuum forming, all layers canbe simultaneously shaped to form the main body of the wind turbinecomponent, in particular to form the continuous and at least partlycurved surface of the main body. This facilitates in particular thefabrication of larger wind turbine components comprising a main body, inparticular with a surface larger than 0.2 m², formed from a layer stack.

In addition, by the choice of the materials of the at least two layersof the layer stack, the resistance to environmental influences and/orthe structural performance, or the structural properties, respectively,of the wind turbine component may be adapted advantageously to theexpected loads on the component and/or under consideration of anattachment position of the wind turbine component on the wind turbine.

The wind turbine component is adapted to be attached to a wind turbine,in particular to a rotor blade of the wind turbine or to a nacelle ofthe wind turbine. The component may be a cover element adapted to coverat least one part of the wind turbine. It is also possible that the windturbine component is an aerodynamic element adapted to be attached to arotor blade of the wind turbine influencing, or in particular enhancing,the aerodynamic properties of the rotor blade.

The wind turbine component is a bearing cover for covering a mainbearing of the wind turbine or the wind turbine component is an edgeprotection cover for covering a leading edge or a trailing edge of arotor blade, or the wind turbine component is an aerodynamic rotor bladeadd-on, in particular a spoiler or a slat.

The component may be attached for instance to a nacelle of the windturbine for covering a main bearing of the wind turbine, which supportsa rotating shaft of the wind turbine connected to a rotor of the windturbine on the nacelle, or a supporting structure of the nacelle,respectively. The component may also be a cover for covering a leadingedge or a trailing edge of the rotor blade, in particular for providinga protection cover for the rotor blade, or its edges, respectively.

Alternatively, the component may be a performance-enhancing aerodynamicrotor blade add-on, which may be attached to a rotor blade to enhanceits aerodynamic properties. The component may be for instance a spoileror a slat, which can be attached for instance with at least one edgeportion to a surface of the rotor blade, wherein a further portion ofthe component may protrude from the surface of the rotor blade in orderto influence the aerodynamic properties of the rotor blade.

The layer stack comprises at least one inner layer and at least oneouter layer, wherein the inner layer is embedded in an outer layerand/or in between at least two outer layers. The inner layer may beembedded in an outer layer, so that the inner layer is completelysurrounded by the material forming the outer layer. It is also possible,that the inner layer is embedded between at least two outer layers,which may consist of different materials.

In an embodiment of the invention, at least one inner layer is asupporting layer and the at least one outer layer is a protective layer,wherein the material of the inner layer is more rigid than the materialof the at least one outer layer. Advantageously, also a cheaper materialcan be used for the supporting layer reducing the cost of the componentwithout affecting the protection provided from the protective layer. Thesupporting layer may provide a stable or essentially stable shape of thecomponent during operation of the wind turbine comprising the component.The inner layer may be protected from environmental influences by theprotective layer. The protective layer is in particular stable in theenvironment of the wind turbine, or during the operation conditions ofthe wind turbine, respectively.

By providing a supporting layer as an inner layer and a protective layeras an outer layer, an overall stronger component can be built due to theincreased freedom of the material choice especially for the inner layer.The inner layer may consist of a material which is not stable in theenvironment of the wind turbine since a protection from this environmentis obtained advantageously using the protective layer as at least oneouter layer.

The layer stack comprises a varying thickness and/or at least onethickness gradient, in particular in a chord-wise direction and/or in aspan-wise direction of the wind turbine component, and/or the layerstack comprises a tapered portion in at least one edge region of themain body, wherein the thickness of the layer stack in the taperedportion decreases towards the edge of the main body.

In particular a component, which is an aerodynamic element adapted to beattached to a rotor blade of the wind turbine, may comprise a layerstack with a varying thickness forming the main body of the component.The varying thickness of the layer stack and hence the varying thicknessof the main body allows for adjusting the shape of the component to theloads acting on the component during the operation of the wind turbine.The thickness may vary in particular in a chord-wise direction and/or ina span-wise direction, wherein the chord-wise direction and thespan-wise direction of the component refer to the chord-wise directionand the span-direction of a rotor blade to which the component isattached in a mounted state of the component.

An aerodynamic element may be attached to a rotor blade in such mannerthat a first portion of the component is fixed to the rotor blade,wherein a second portion of the component protrudes from a surface ofthe rotor blade. The first portion, or the attachment portion,respectively, may have a larger thickness than the second portion, orthe protruding portion, respectively. It is possible that the thicknessdecreases continuously in the attachment portion and the protrudingportion so that in particular a thickness gradient of the component isobtained. The thickness of the component may decrease at least in theprotruding portion in chord-wise direction, since the loads acting onthe protruding portion may decrease with increasing distance from thesurface of the rotor blade, or the attachment portion, respectively.

Providing a tapered portion in at least one edge region of the main bodyallows for attaching the component with its edge region to the windturbine, in particular to a rotor blade of the wind turbine and/or to anacelle of the wind turbine. The thickness of the layer stack and hencethe thickness of the main body in the tapered portion decrease towardsthe edge of the main body, so that by attaching the edge portion asattachment portion to the surface of the wind turbine, a smoothtransition between the surface of the wind turbine, in particular ashell of a rotor blade, and the component is obtained.

The thickness of the layer stack in the tapered portion may decreasecontinuously towards the edge of the main body. The thickness variationand/or a thickness gradient of the component may be determined independence of a calculated and/or simulated stress distribution and/orin dependence of expected loads acting on the component during envisagedoperational states of a wind turbine comprising the component. Thevarying thickness and/or the thickness gradient may be created by usingone or more layers of the layer stack that exhibit a varying thicknessand/or a thickness gradient, so that also a layer stack comprising oneor more of such layers exhibits a varying thickness and/or a thicknessgradient.

At least one of the layers of the layer stack comprises a plasticmaterial. A layer fabricated of for instance an environmentally stableplastic material may cover for instance an inner layer, which is made ofa different material, in particular a different plastic providing theshape of the main body, or of the component, respectively. It ispossible that a material forming a layer of the layer stack may comprisefurther elements, for instance fibres, that are embedded in a matrix, orthe like.

In an embodiment of the invention, the layer stack comprises at leastone sensing layer, wherein the sensing layer comprises at least oneelectrically conductive and/or optically conductive and/orpiezo-resistive material, and/or the layer stack comprises at least oneactive layer for changing a geometry and/or a property of the component.The sensing layer and/or the active layer may be in particular an innerlayer as previously described. It is in particular possible that thesensing layer and/or the active layer is arranged next to a supportinglayer as further inner layer, wherein the supporting layer and thesensing layer, or the active layer, respectively, are embedded in anouter layer and/or in between at least two outer layers.

By providing a sensing layer comprising an electrically conductiveand/or optically conductive and/or piezo-resistive material, at leastone property of the sensing layer may be measured, wherein a measurementvalue describing the property may be used as a measure for loads actingon the component during operation of a wind turbine comprising thecomponent. Additionally or alternatively, the measurement value may beused for determination of a state of the component, for instance todetect a damaged or worn component.

By measuring for instance an electrical resistance and/or an opticalabsorption of the sensing layer and/or by evaluating effects likeoptical scattering or the like in the sensing layer, a force acting onthe component during operation of the wind turbine may be determined. Inaddition, also a state of the component, for instance a damaged or worncomponent, can be detected by measuring at least one property of thesensing layer.

The provision of the sensing layer as a layer of the layer stack has theadvantage that the sensing layer is integrated in the component as asensing means so that a usage of further sensors is not necessary.Furthermore, since the sensing layer is provided as a part of the layerstack forming the main body of the component, the sensing layer mayextend in the main body in particular over the entire component, or atleast over a large portion of the component, respectively.Advantageously, this allows for detecting damage or wear of thecomponent in a large area of the component, or in the entire component,respectively. The provision of the sensing layer as a part of the layerstack facilitates the manufacturing of the component since the entiremain body including the sensing layer may be formed in particular in asingle production step from the layer stack.

For measuring the property of the sensing layer, the sensing layer maycomprise at least one contact portion protruding for instance through anouter layer covering the sensing layer at least partly, so that thesensing layer may be connected to a control unit adapted to determine atleast one measurement value describing the at least one property of thesensing layer. The control unit may be a part of the wind turbinecomponent or a part of the wind turbine, wherein in the latter case thewind turbine component is connected to the control unit for instanceafter attachment of the component to the wind turbine.

The sensing layer may comprise for instance a metal as an electricallyconductive material and/or glass fibres as an optically conductivematerial. Additionally or alternatively, also a piezo-resistive materialmay be use as sensing layer. The material of the sensing layer may beprovided as a continuous layer of the layer stack. It is also possiblethat the material of the sensing layer is provided in shape of a mesh ora grid and/or that the electrically and/or optically conductive and/orpiezo-resistive material is embedded in a further material, for instancea plastic material and/or a resin.

By actuating the active layer, the geometry of the active layer or aproperty of the active layer, for instance a mechanical property like aflexibility or a rigidity may be changed. By changing the geometry ofthe active layer also the geometry of the component may be changed.Correspondingly, by changing a property of the active layer, also aproperty of the component may be changed. For example, using the activelayer allows for adjusting the geometry and/or a property of thecomponent during operation of the wind turbine, or during operation ofthe component, respectively. The adjustment of the component may occurfor instance in dependence of the operating conditions and/or independence of a state of the component, for instance in dependence of astate determined using a sensing layer of the component as previouslydescribed.

The active layer may comprise for instance a piezo-electrical material,so that by applying a voltage to the active layer by an actuationarrangement of the wind turbine, or of the component, respectively, thegeometry of the active layer and/or a property of the active layer maybe changed. Additionally or alternatively, the active layer may comprisea heating arrangement and a material with a temperature-dependinggeometry and/or at least one temperature-depending property, so that thegeometry and/or the property may be changed by heating the active layerusing the heating arrangement of the active layer. The heatingarrangement may be for instance an electrically conductive and/or anoptically conductive material which is heated by applying an electriccurrent and/or light to the heating arrangement using an actuationarrangement connected to the active layer.

A wind turbine according to embodiments of the invention comprises atleast one wind turbine component according to embodiments of theinvention.

According to embodiments of the invention, a method for manufacturing awind turbine component, wherein the wind turbine component comprises amain body with a continuous and at least partly curved surface,comprises the steps:

-   -   Providing a layer stack comprising a plurality of planar or        essentially planar layers, wherein at least two of the layers        consist of a different material,    -   Fabricating the main body from the layer stack, wherein the        continuous and at least partly curved surface of the main body        is formed in a vacuum forming process.

The layers of the plurality of planar or essentially planar layers ofthe layer stack may for instance be attached to at least one neighboringlayer so that a stable stack is obtained. The layers may be stacked inthe direction of their thicknesses, wherein a width and/or length of thelayer stack may correspond to a width or a length, respectively, of thecomponent to be manufactured. Essentially planar means that the layermay comprise a varying thickness and/or a thickness gradient in a widthdirection and/or a length direction of the layer, wherein the thicknessis, in particular significantly, smaller than the width and/or thelength of the layer so that the layer, or the layer stack comprising thelayer, respectively, may be formed using the vacuum forming process.

From the layer stack, the main body of the component comprising acontinuous and at least partly curved surface is fabricated in a vacuumforming process, in which the layer stack is shaped accordingly to thedesired final shape of the component. In the vacuum forming process, thelayer stack may be sucked in a mould using a vacuum, wherein the shapeof the mould corresponds to the shape of the component to bemanufactured. By the vacuum forming process, the layer stack adopts theshape of the mould so that the continuous and at least partly curvedsurface of the main body of the component may be formed advantageously.The stacking of the layers from the layer stack is in particularmaintained during the forming of the main body in the vacuum formingprocess.

A layer stack comprising at least one inner layer and at least one outerlayer is used, wherein the inner layer is embedded in an outer layerand/or in between at least two outer layers.

A layer stack with a supporting layer as the at least one inner layerand a protective layer as the at least one outer layer is used, whereinthe material of the inner layer is more rigid than the material of theat least one outer layer.

By providing both the at least one inner layer and the at least oneouter layer as a layer stack prior to the forming of the component, thefabrication of larger components in one single step is facilitated.Furthermore, by providing an inner layer and an outer layer each with adifferent material, stronger components can be built due to theincreased freedom in choosing the materials of the inner layer and/orthe outer layer. The provision of the layer stack comprising a pluralityof layers for forming the component in the vacuum forming process allowsfor combining different materials in form of different layers to betterbalance the need between the costs of the manufacture and theengineering requirements, or the properties, respectively, of the windturbine component.

A layer stack comprising a varying thickness and/or at least onethickness gradient, in particular in a chord-wise direction and/or in aspan-wise direction of the wind turbine component, is used and/or alayer stack comprising a tapered portion in at least one edge region ofthe layer stack is used, wherein the thickness of the layer stack in thetapered portion decreases towards the edge of the layer stack, whereinthe tapered portion is used to form an edge region of the main bodyduring fabrication of the main body.

The tapered portion of the layer stack may be used to form an edgeregion of the main body of the wind turbine component duringfabrication. As a result, also the main body formed from the layer stackcomprises a tapered edge portion facilitating the fixation of thecomponent to a surface of a wind turbine. In particular, in case of anaerodynamic element or a cover element that is attached to a rotorblade, a smooth transition between the component attached to the rotorblade and a surface of the rotor blade, or a shell of the rotor blade,respectively, is obtained.

A layer stack with at least one layer comprising a plastic material isused. A layer of an environmentally stable plastic material may form inparticular an outer layer of the layer stack embedding at least partlyone or more inner layers of the layer stack.

In an embodiment of the invention, a layer stack comprising at least onesensing layer is used, wherein the sensing layer comprises at least oneelectrically conductive and/or optically conductive and/orpiezo-resistive material, and/or a layer stack comprising at least oneactive layer for changing a geometry and/or a property of the componentis used.

The sensing layer and/or the active layer is in particular an innerlayer covered by or embedded in at least one outer layer in order toprotect the sensing layer from environmental influences. The sensinglayer may consist of or comprise a metal and/or glass fiber structuresand/or piezo-resistive material. It is possible that the material of thesensing layer is provided as a continuous layer or that the material ofthe sensing layer is provided as a mesh or a grid and/or that theelectrically and/or optically conductive and/or piezo-resistive materialis embedded in a further material, for instance a plastic materialand/or a resin.

The active layer may comprise for instance a piezo-electrical materialand/or a material with a temperature-depending geometry and/or at leastone temperature-depending property. In the latter case, the active layermay comprise a heating arrangement, for instance an electricallyconductive and/or an optically conductive material, which is provided asa continuous layer and/or as a mesh structure embedded in the activelayer.

The sensing layer and/or the active layer may have at least one contactportion protruding through the at least one outer layer of the componentto allow for connecting the sensing layer after fabrication of thecomponent. A connection to the at least one sensing layer may beestablished for example from a control unit of a wind turbine in orderto measure a physical property of the sensing layer as a measure for aload acting on the component and/or for determining a state, forinstance a damaged or worn state of the component, as previouslydescribed. A connection to the active layer may be established forexample from an actuator arrangement of the wind turbine in order tochange the geometry and/or a property of the active layer, as previouslydescribed.

As wind turbine component, a cover element, in particular a bearingcover for covering a main bearing of the wind turbine or an edgeprotection cover for a leading edge or a trailing edge of a rotor blade,or an aerodynamic element, in particular an aerodynamic rotor bladeadd-on, especially a spoiler or a slat, is fabricated.

All details and advantages described in relation to the wind turbinecomponent according to embodiments of the invention applycorrespondingly to the wind turbine according to embodiments of theinvention and to the method for manufacturing of a wind turbine bladecomponent and vice versa.

Some of the embodiments will be described in detail, with reference tothe following figures, wherein like designations denote like members,wherein:

FIG. 1 shows an embodiment of a wind turbine according to the invention;

FIG. 2 shows a layer stack used for forming a main body of a windturbine component;

FIG. 3 shows a first embodiment of a wind turbine component according tothe invention;

FIG. 4 shows a second layer stack used for forming a main body of a windturbine component;

FIG. 5 shows a second embodiment of a wind turbine component accordingto the invention; and

FIG. 6 shows a third embodiment of a wind turbine component according tothe invention.

DETAILED DESCRIPTION

In FIG. 1 , a wind turbine 1 according to embodiments of the inventionis shown. The wind turbine 1 comprises a tower 2, wherein on top of thetower 2 a nacelle 3 of the wind turbine 1 is arranged. Inside thenacelle 3, a generator (not shown) of the wind turbine 1 isaccommodated, wherein the generator is connected to a hub 4 of the windturbine via a main shaft 5 of the wind turbine 1. On the hub 4, aplurality of rotor blades 5 is mounted.

On each of the rotor blades 5, a plurality of wind turbine components 6is attached, wherein the components 6 attached to the rotor blades 5 areeach a cover element 7 covering a leading edge 8 of the rotor blades 5or an aerodynamic element 9, in particular an aerodynamic rotor bladeadd-on that enhances the performance of the rotor blade 5, or of thewind turbine 1, respectively. The aerodynamic elements 9 are forinstance spoilers or slats mounted to a surface, or a shell,respectively, of the rotor blades 5.

One of the wind turbine components 6 is a bearing cover 10 covering amain bearing of the wind turbine 1, which supports the shaft 5 on thenacelle 3, or on a supporting structure of a nacelle 3, respectively.The bearing cover 10 is attached to the nacelle 3 of the wind turbine 1.

Each of the components 6 comprises a main body 11 formed by a layerstack 12 comprising a plurality of layers, wherein at least two of thelayers consists of a different material. The components may befabricated in an embodiment of a method for manufacturing of a windturbine component according to embodiments of the invention described inrelation to the following figures.

In FIG. 2 , a layer stack 12 for forming a main body 11 of a component 6is shown. The layer stack 12 comprises an inner layer 13, which isembedded in an outer layer 14. The inner layer 13 is a supporting layerconsisting of a material, which is more rigid than the material of theat least one outer layer 14. The inner layer 13 provides a mechanicalstability and/or a shape stability of the component 6 fabricated fromthe layer stack 12.

Furthermore, the layer stack 12 comprises a sensing layer 15, which isalso an inner layer and which is embedded in the outer layer 14. Theouter layer 14 is a protective layer protecting the inner layer 13 andthe sensing layer 15 from environmental influences. The inner layer 13and the outer layer 14 consist of different materials, in particularthey may each consist of a different plastic material.

The sensing layer 15 comprises at least one electrically conductiveand/or optically conductive and/or piezo-resistive material. The sensinglayer 15 may comprise for instance a metal or a plurality of glassfibres or glass fibres-based materials, respectively. The material ofthe sensing layer 15 may be provided as a planar and a continuous layeror as a mesh or a grid. The material of the sensing layer 15 may beembedded in a further material of the sensing layer 15, for instance ina plastic and/or in a resin. The sensing layer 15 may be fixed to theinner layer 13 and/or to the outer layer 14 so that a stable layer stack12 is provided.

The layer stack 12 comprises a tilted edge portion 16, in which athickness of the layer stack 12 decreases. From the layer stack 12, awind turbine component 6 may be formed in a vacuum-based formingprocess. In this process, the layer stack 12 may be sucked in a mouldusing a vacuum, wherein the mould comprises a shape corresponding to thecomponent 6 to be fabricated from the layer stack 12. During this vacuumforming process, the layer stack 12 adopts to the shape of the mouldforming the main body 11 of the component 6. The planar layers of thelayer stack 12 are formed in the vacuum forming process to build themain body 11 comprising a continuous and curved surface 19 of thecomponent 6.

In FIG. 3 , a wind turbine component 6 fabricated from the layer stack12 depicted in FIG. 2 is shown. The wind turbine component 6 is anaerodynamic element 9, in particular a spoiler or a slat, which is shownattached to a surface 17 of a shell of the rotor blade 5. The attachmentof the component 6 to the surface 17 of the rotor blade 5 may occur forinstance using fastening means and/or one or more adhesive layers 18fixating the component 6 to the surface 17.

From the tilted portion 16 of the layer stack 12, an edge region of themain body 11 is formed during manufacturing of the component 6. Byproviding the tilted edge portion 16 of the layer 12, also a tilted edgeportion of the component 6, or of its main body 11, respectively, isobtained enabling a smooth transition between the surface 17 of therotor blade 5 and the component 6. In particular, a height of thecomponent 6, or its thickness, respectively, in a portion directed tothe leading 8 of the rotor blade 5 in a mounted state of the component 6may be reduced advantageously.

In FIG. 4 , a second embodiment of the layer stack 12 for forming a mainbody 11 of a component 6 is shown. In this embodiment, the layer stack12 comprises an additional thickness gradient in a chord-wise directionof the wind turbine component 6. From this layer stack 12, a windturbine component with a reduced thickness in a chord-wise direction isformed. The chord-wise direction of the component 6 refers to thechord-wise direction of the rotor blade 5 to which the component 6 ismounted in such manner, that one of the dimensions of the componentsextends parallelly to the chord-wise direction of the rotor blade 5, sothat this dimension forms the chord-wise direction of the component 6.In FIG. 4 , the chord-wise direction of the component 6 extends fromleft to right, or from right to left, respectively. By providing thelayer stack 12 with at least one thickness gradient in chord-wisedirection, the shape of the component 6 formed from the layer stack 12may be adapted to loads acting on the component 6 during operation ofthe wind turbine 1.

As depicted in FIG. 5 , from the layer stack 12 shown in FIG. 4 , anaerodynamic element 9 is formed as previously described, wherein thethickness of the aerodynamic element 9 decreases in chord-wisedirection, in particular in a portion of the component 6 which protrudesfrom the surface 17 of the rotor blade 5.

The protruding portion of the aerodynamic element 9 is supported on thesurface 17 of the rotor blade by a further aerodynamic element 20,wherein the further aerodynamic element 20 influences the aerodynamicproperties of the aerodynamic element 9. The further aerodynamic element20 comprises a main body 21 with a continuous and at least partly curvedsurface, wherein the main body 21 is formed from a layer stack 22comprising an inner layer 23 and an outer layer 24. Also, the furthercomponent 20 may be manufactured from the layer stack 22 as previouslydescribed. It is possible that also the further aerodynamic element 20comprises a sensing layer. Besides aerodynamic elements 9, 20 alsoprotective cover elements like the bearing cover 10 or edge protectioncovers 7 may be fabricated.

In FIG. 6 , a component 6 forming a cover element 7, which is an edgeprotection cover 25, is shown attached to the leading edge 8 of a rotorblade 5. Also, the cover element 7 is fabricated from a layer stack 12comprising an inner layer 13, an outer layer 14 and a sensing layer 15as previously described in correspondence to the aerodynamic elements 9.The layer stack 12, or the cover element 7, respectively, comprises twotilted edge sections 16 allowing for a smooth transition between thecover element 7 and the surface 17 of the rotor blade 5. Alternatively,the edge protection cover 25 may be a trailing edge cover covering atrailing edge of the rotor blade 5.

In all embodiments, the sensing layer 15 may comprise a contact portionprotruding the outer layer 14, so that the sensing layer 15 may beconnected to a control unit of the component 6, or of the wind turbine1, respectively. The control unit may be adapted to measure at least onephysical property of the sensing layer 15, for instance an electricalresistance, an optical absorption, optical scattering or the like, inorder to determine a load acting on the component and/or a state of thecomponent 6. This allows for instance to detect operational states, inwhich the load acting on the component 6 is too high and/or to detect acomponent 6 that has been damaged or worn during operation.

In all embodiments, it is possible that the inner layers 13, 23 and/orthe sensor layer 15 are embedded between two outer layers 14, 24 eachconsisting of a different material. This allows further adapting thecharacteristics of the components 6 to their use-case in the windturbine 1. In all embodiments, the layer stacks 12, 22, or thecomponents 6, 20 respectively, may comprise a varying thickness and/or athickness gradient in span-wise direction, which is orthogonal to thedrawing plane in FIG. 2 to 6 .

In all embodiments, an active layer may be used as an alternative to thesensing layer 15 or in addition to the sensing layer 15. The activelayer may be arranged as an inner layer or as an outer layer of a layerstack 12, 22. It is also possible that the active layer and/or thesensing layer 15 and/or further layers of a layer stack 12, 22 arestacked one on top of another in different orders.

By actuating an active layer in the layer stack 12, 22, the geometry ofthe active layer or a property of the active layer, for instance amechanical property like a flexibility or a rigidity may be changed. Bychanging the geometry of the active layer, also the geometry of thecomponent 6 may be changed. Correspondingly, by changing a property ofthe active layer, also a property of the component 6 may be changed.

Using the active layer allows for adjusting the geometry and/or aproperty of the component 6 during operation of the wind turbine 1, orduring operation of the component 6, respectively. The adjustment of thecomponent 6 may occur for instance in dependence of the operatingconditions and/or in dependence of a state of the component 6, forinstance in dependence of a state determined using a sensing layer 15 ofthe component 6 as previously described.

The active layer may comprise for instance a piezo-electrical material,so that by applying a voltage to the active layer by an actuationarrangement of the wind turbine 1, the geometry of the active layerand/or a property of the active layer may be changed. Additionally oralternatively, the active layer may comprise a heating arrangement and amaterial with a temperature-depending geometry and/or at least onetemperature-depending property, so that the geometry and/or the propertymay be changed by heating the active layer using the heating arrangementof the active layer. The heating arrangement may be for instance anelectrically conductive and/or an optically conductive material which isheated by applying an electric current and/or light to the heatingarrangement using an actuation arrangement connected to the activelayer.

Although the present invention has been disclosed in the form ofembodiments and variations thereon, it will be understood that numerousadditional modifications and variations could be made thereto withoutdeparting from the scope of the invention.

For the sake of clarity, it is to be understood that the use of “a” or“an” throughout this application does not exclude a plurality, and“comprising” does not exclude other steps or elements.

1. A wind turbine component adapted to be attached to a wind turbine,wherein the component is a cover element adapted to cover at least onepart of a wind turbine or an aerodynamic element adapted to be attachedto a rotor blade of a wind turbine, wherein the component comprises amain body with a continuous and at least partly curved surface, whereinthe main body is formed by a layer stack comprising a plurality oflayers, wherein at least two of the layers consist of a differentmaterial.
 2. The wind turbine component according to claim 1, whereinthe layer stack comprises at least one inner layer and at least oneouter layer, wherein the inner layer is embedded in an outer layerand/or in between at least two outer layers.
 3. The wind turbinecomponent according to claim 2, wherein the at least one inner layer isa supporting layer and the at least one outer layer is a protectivelayer, wherein the material of the inner layer is more rigid than thematerial of the at least one outer layer.
 4. The wind turbine componentaccording to claim 1, wherein the layer stack comprises a varyingthickness and/or at least one thickness gradient, in at least one of achord-wise direction and/or in a span-wise direction of the wind turbinecomponent, and/or that the layer stack comprises a tapered portion in atleast one edge region of the main body, wherein the thickness of thelayer stack in the tapered portion decreases towards the edge of themain body.
 5. The wind turbine component according to claim 1, whereinat least one of the layers of the layer stack comprises a plasticmaterial.
 6. The wind turbine component according to claim 1, whereinthe layer stack comprises at least one sensing layer, wherein thesensing layer comprises at least one electrically conductive and/oroptically conductive and/or piezo-resistive material and/or that thelayer stack comprises at least one active layer for changing a geometryand/or a property of the component.
 7. The wind turbine componentaccording to claim 1, wherein the wind turbine component is a bearingcover for covering a main bearing of the wind turbine or that the windturbine component is an edge protection cover for covering a leadingedge or a trailing edge of a rotor blade or that the wind turbinecomponent is an aerodynamic rotor blade add-on.
 8. The wind turbinecomprising at least one wind turbine component according to claim
 1. 9.A method for manufacturing of a wind turbine component, wherein the windturbine component comprises a main body with a continuous and at leastpartly curved surface, comprising the steps: providing a layer stackcomprising a plurality of planar or essentially planar layers, whereinat least two of the layers are of a different material, fabrication themain body from the layer stack, wherein the continuous and at leastpartly curved surface of the main body is formed in a vacuum formingprocess.
 10. The method according to claim 9, wherein a layer stackcomprising at least one inner layer and at least one outer layer isused, wherein the inner layer is embedded in an outer layer; and/or inbetween at least two outer layers.
 11. The method according to claim 10,wherein a layer stack with a supporting layer as the at least one innerlayer and a protective layer as the at least one outer layer is used,wherein the material of the inner layer is more rigid than the materialof the at least one outer layer.
 12. The method according to claim 9,wherein a layer stack comprising at least one of a varying thicknessand/or at least one thickness gradient, are in at least one of achord-wise direction and/or in a span-wise direction of the wind turbinecomponent, is used and/or that a layer stack comprising a taperedportion in at least one edge region of the layer stack is used, whereinthe thickness of the layer stack in the tapered portion decreasestowards the edge of the layer stack, wherein the tapered portion is usedto form an edge region of the main body during fabrication of the mainbody.
 13. The method according to claim 9, wherein a layer stack with atleast one layer comprising a plastic material is used.
 14. The methodaccording to claim 9, wherein a layer stack comprising at least onesensing layer is used, wherein the sensing layer comprises at least oneelectrically conductive and/or optically conductive and/orpiezo-resistive material, and/or that a layer stack comprising at leastone active layer for changing a geometry and/or a property of thecomponent is used.
 15. The method according to claim 9, wherein as windturbine component, a cover element is manufactured.
 16. The wind turbinecomponent according to claim 7, the aerodynamic rotor blade add-on is aspoiler or a slat.
 17. The method according to claim 15, the coverelement, is a bearing cover for covering a main bearing of the windturbine or an edge protection cover for a leading edge or a trailingedge of a rotor blade, is manufactured.